1. Field
The present invention relates to industrial processes for cleaning an undesirable, dirty residue from the surfaces of metal articles, wherein the undesirable, dirty residues which have been left on the metal articles from previous metal working operations, are cleaned from the metal articles at ambient temperature and at an economically feasible cost.
2. State of the Art
The metal working industry uses numerous methods for stamping, cutting, welding, grinding, drawing, machining and polishing the myriad of metal parts and products which are produced. As a result of such metal working operations, an undesirable, dirty residue is left on the surfaces of the metal parts and products. The dirty residue must be removed in most situations before the metal parts or products are employed for their desired use.
In order to achieve this cleaning at an ambient temperature, it has been common to use degreasing compositions such as methyl ethyl ketone, and methylene chloride and other polyhalogenated and aliphatic and aromatic hydrocarbons to remove grease and oil from metal parts. However, these compositions are rather expensive and are pollutants of the environment which are difficult to dispose of. Further, these compositions must be handled with care to avoid costly losses of the compositions. Because of the costly nature of the compositions, elaborate apparatus and processes must be used to reclaim the dirty compositions for reuse. In addition, many of the compositions present particular hazards to anyone who may come in contact with the compositions or harmful vapors thereof. To avoid the costs associated with the degreasing compositions, it has been proposed to utilize a strong aqueous based cleaning composition. Almost universally, aqueous hot alkaline cleaning solutions are used.
To achieve satisfactory cleaning of metal articles which have been subjected to a previous metal working operation, the alkaline cleaning solutions must be heated to a temperature of from about 130.degree. F. to 150.degree. F. The cost of heating the cleaning solutions is significant and greatly ameliorates the advantage which such solutions otherwise have in being initially less expensive than the degreasing compositions mentioned previously. In addition, the handling of hot alkaline solutions create other less tangible problems including increased maintenance and reduced equipment life.
3. Objectives
It is a principal objective of the present invention to provide a novel, unique process for cleaning metal articles which have an undesirable, dirty residue left on the surfaces thereof, wherein a novel, aqueous based cleaning solution is used and the cleaning is accomplished at ambient temperatures of from about 4.degree. C. to 40.degree. C.
A particular objective of the present invention is to provide a process which results in a high, completely acceptable cleaning efficiency even when the process is operated at ambient temperatures as low as 4.degree. C.
A further objective of the present invention is to provide a process for cleaning metal articles using a novel, aqueous based cleaning solution wherein increased equipment life and reduced maintenance is experienced in comparison to conventional cleaning processes utilizing a hot alkaline cleaning composition.
An additional objective of the present invention is to provide novel lubricating compositions and polishing compositions for use in metal treating operations, wherein the dirty residues left on the metal articles are more readily removed during subsequent procedures for cleaning the metal articles.